ABSTRACT Objective: Percutaneous ethanol injection (PEI) is an alternative to surgery for the treatment of thyroid nodules (TNs). However, size reductions of treated (TTNs) and untreated TN (UTNs) have not been compared. Volumetric reductions in TTNs with PEI were evaluated by comparing TTNs and UTNs in the same patient, and independent variables predicting good post-PEI outcomes were analyzed. Materials and methods: Overall, 282 patients with multinodular goiters were selected. Two nodules located in different lobes were compared for common disease behaviors. Overall, 150 nodules were selected from 75 patients (6 M: 69 F) with a mean age of 50.1 ± 17.4 years. This prospective nonrandomized intervention study prioritized treating TNs of greater volume or single hyperfunctioning TNs. A single observer experienced in PEI and an ultrasound specialist performed the interventions. Results and discussion: TTNs (mean volume: 14.8 ± 16.2 mL) were reduced by 72.6 ± 27.3% of their initial volume, while UTNs increased by a mean of 365.7 ± 1.403.8% (p < 0.00001). The patients underwent a mean of 4.0 ± 3.1 outpatient PEI sessions without relevant complications. Logistic regression analysis showed that the magnitude of the PEI induced reduction was associated with the number of treatment sessions (p = 0.03, CI [1.1-38.2]) and not with ultrasonographic characteristics of the nodules. Each PEI session increased the rate of TN reduction by a factor of 6.7. Conclusions: PEI is a well-tolerated outpatient procedure that effectively reduces the volume of TNs and is noticeably superior to conservative treatment for all ultrasonographic classifications.

OBJETIVO: Verificar o efeito da injeção percutânea de etanol guiada por ultra-sonografia no tratamento dos nódulos tireoidianos císticos. MATERIAIS E MÉTODOS: Comparou-se o volume de 34 nódulos benignos císticos, em 30 pacientes (26 do sexo feminino e quatro do sexo masculino), antes e uma média de 3,9 meses depois da alcoolização. O volume inicial dos nódulos foi avaliado por dois observadores, que realizaram a ultra-sonografia em momentos diferentes, sem qualquer informação prévia a respeito do tamanho dos nódulos, cuja finalidade foi conhecer a variação interobservador das medidas ecográficas. RESULTADOS: A média de volume dos nódulos antes do tratamento foi de 12,3 ± 18,0 ml. A média de redução de volume foi de 74,0 ± 26,1% (p = 0,0001), e 20,6% (7/34) deles desapareceram. Não houve correlação entre o volume inicial e o percentual de redução dos nódulos. A média de variação das medidas interobservadores foi de 0,5 ml para um alfa de 5%. Dor moderada, no momento da aplicação, foi a complicação mais freqüente. CONCLUSÃO: A injeção percutânea de etanol é uma opção segura e eficaz no tratamento dos nódulos tireoidianos císticos.

OBJECTIVE: To check the effect of ultrasound-guided percutaneous ethanol injection for treatment of cystic thyroid nodules. MATERIALS AND METHODS: A comparison was made of the volume of 34 benign cystic nodules in 30 patients (26 female, four male), before and 3.9 months (on average) after alcoholization. For the purpose of finding out interobserver variations in echographic measurements, the initial volume of the nodules was assessed by means of ultrasound at different moments, by two observers, without any previous knowledge on the nodules size. RESULTS: Mean volume of nodules before treatment was 12.3 ± 18.0 ml. Mean reduction rate in nodules after alcoholization was 74.0 ± 26.1% (p < 0.0001) and 7/34 (20.6%) of the nodules disappeared. There was no correlation between nodules size and reduction rate. The average interobserver nodule measurement variation was 0.5 ml, for an alpha of 5%. Moderate pain at the time of injection was the most frequent complication. CONCLUSION: Ultrasound-guided percutaneous ethanol injection is a safe and effective option for treatment of cystic thyroid nodules.